1. Field of the Invention
The invention relates to a lip seal for sealing cylindrical surfaces, especially those of input and output hydraulic cylinders in motor vehicles, axially fixed in a cylindrical part of a cylinder housing with a first sealing lip directed against the cylinder housing and a second sealing lip directed against a cylindrical surface of a piston which is axially movably within the cylinder housing.
2. Description of the Related Art
German reference DE 195 23 011 A1 discloses a hydraulic clutch release device for a friction clutch having a housing. A telescopic piston including a primary piston and a secondary piston is arranged in a central recess, of the housing for the purpose of attaining reduced structural length. The primary piston has a lip seal with an inwardly directed sealing lip and an outwardly directed sealing lip on its ring-shaped front face. The lip seal is mounted and held in its position with the primary piston in an annular groove in the front face of the primary piston. This fixing of the lip seal is required to neutralize tilting moments that occur as the result of the translatory movements in different directions of the outer cylindrical surface relative to the inner cylindrical surface.